diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index 6d5e89ce2..3201d60ff 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -335,6 +335,12 @@ TypeNameAnnotation& TypeName::annotation() const
 	return initAnnotation<TypeNameAnnotation>();
 }
 
+Type const* UserDefinedValueTypeDefinition::type() const
+{
+	solAssert(m_underlyingType->annotation().type, "");
+	return TypeProvider::typeType(TypeProvider::userDefinedValueType(*this));
+}
+
 Type const* StructDefinition::type() const
 {
 	solAssert(annotation().recursive.has_value(), "Requested struct type before DeclarationTypeChecker.");
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index f02e93599..e1e5fc596 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -726,6 +726,37 @@ public:
 	Type const* type() const override;
 };
 
+/**
+ * User defined value types, i.e., custom types, for example, `type MyInt is int`. Allows creating a
+ * zero cost abstraction over value type with stricter type requirements.
+ */
+class UserDefinedValueTypeDefinition: public Declaration
+{
+public:
+	UserDefinedValueTypeDefinition(
+		int64_t _id,
+		SourceLocation const& _location,
+		ASTPointer<ASTString> _name,
+		SourceLocation _nameLocation,
+		ASTPointer<TypeName> _underlyingType
+	):
+		Declaration(_id, _location, _name, std::move(_nameLocation), Visibility::Default),
+		m_underlyingType(std::move(_underlyingType))
+	{
+	}
+
+	void accept(ASTVisitor& _visitor) override;
+	void accept(ASTConstVisitor& _visitor) const override;
+
+	Type const* type() const override;
+
+	TypeName const* underlyingType() const { return m_underlyingType.get(); }
+
+private:
+	/// The name of the underlying type
+	ASTPointer<TypeName> m_underlyingType;
+};
+
 /**
  * Parameter list, used as function parameter list, return list and for try and catch.
  * None of the parameters is allowed to contain mappings (not even recursively
diff --git a/libsolidity/ast/ASTForward.h b/libsolidity/ast/ASTForward.h
index 5b73eb3a3..79e6a4ecf 100644
--- a/libsolidity/ast/ASTForward.h
+++ b/libsolidity/ast/ASTForward.h
@@ -51,6 +51,7 @@ class UsingForDirective;
 class StructDefinition;
 class EnumDefinition;
 class EnumValue;
+class UserDefinedValueTypeDefinition;
 class ParameterList;
 class FunctionDefinition;
 class VariableDeclaration;
diff --git a/libsolidity/ast/ASTVisitor.h b/libsolidity/ast/ASTVisitor.h
index 398387b33..ef03e6339 100644
--- a/libsolidity/ast/ASTVisitor.h
+++ b/libsolidity/ast/ASTVisitor.h
@@ -61,6 +61,7 @@ public:
 	virtual bool visit(IdentifierPath& _node) { return visitNode(_node); }
 	virtual bool visit(InheritanceSpecifier& _node) { return visitNode(_node); }
 	virtual bool visit(UsingForDirective& _node) { return visitNode(_node); }
+	virtual bool visit(UserDefinedValueTypeDefinition& _node) { return visitNode(_node); }
 	virtual bool visit(StructDefinition& _node) { return visitNode(_node); }
 	virtual bool visit(EnumDefinition& _node) { return visitNode(_node); }
 	virtual bool visit(EnumValue& _node) { return visitNode(_node); }
@@ -116,6 +117,7 @@ public:
 	virtual void endVisit(IdentifierPath& _node) { endVisitNode(_node); }
 	virtual void endVisit(InheritanceSpecifier& _node) { endVisitNode(_node); }
 	virtual void endVisit(UsingForDirective& _node) { endVisitNode(_node); }
+	virtual void endVisit(UserDefinedValueTypeDefinition& _node) { endVisitNode(_node); }
 	virtual void endVisit(StructDefinition& _node) { endVisitNode(_node); }
 	virtual void endVisit(EnumDefinition& _node) { endVisitNode(_node); }
 	virtual void endVisit(EnumValue& _node) { endVisitNode(_node); }
@@ -194,6 +196,7 @@ public:
 	virtual bool visit(InheritanceSpecifier const& _node) { return visitNode(_node); }
 	virtual bool visit(StructDefinition const& _node) { return visitNode(_node); }
 	virtual bool visit(UsingForDirective const& _node) { return visitNode(_node); }
+	virtual bool visit(UserDefinedValueTypeDefinition const& _node) { return visitNode(_node); }
 	virtual bool visit(EnumDefinition const& _node) { return visitNode(_node); }
 	virtual bool visit(EnumValue const& _node) { return visitNode(_node); }
 	virtual bool visit(ParameterList const& _node) { return visitNode(_node); }
@@ -248,6 +251,7 @@ public:
 	virtual void endVisit(IdentifierPath const& _node) { endVisitNode(_node); }
 	virtual void endVisit(InheritanceSpecifier const& _node) { endVisitNode(_node); }
 	virtual void endVisit(UsingForDirective const& _node) { endVisitNode(_node); }
+	virtual void endVisit(UserDefinedValueTypeDefinition const& _node) { endVisitNode(_node); }
 	virtual void endVisit(StructDefinition const& _node) { endVisitNode(_node); }
 	virtual void endVisit(EnumDefinition const& _node) { endVisitNode(_node); }
 	virtual void endVisit(EnumValue const& _node) { endVisitNode(_node); }
diff --git a/libsolidity/ast/AST_accept.h b/libsolidity/ast/AST_accept.h
index 075e6fe5c..14ebfe621 100644
--- a/libsolidity/ast/AST_accept.h
+++ b/libsolidity/ast/AST_accept.h
@@ -164,6 +164,26 @@ void EnumValue::accept(ASTConstVisitor& _visitor) const
 	_visitor.endVisit(*this);
 }
 
+void UserDefinedValueTypeDefinition::accept(ASTConstVisitor& _visitor) const
+{
+	if (_visitor.visit(*this))
+	{
+		if (m_underlyingType)
+			m_underlyingType->accept(_visitor);
+	}
+	_visitor.endVisit(*this);
+}
+
+void UserDefinedValueTypeDefinition::accept(ASTVisitor& _visitor)
+{
+	if (_visitor.visit(*this))
+	{
+		if (m_underlyingType)
+			m_underlyingType->accept(_visitor);
+	}
+	_visitor.endVisit(*this);
+}
+
 void UsingForDirective::accept(ASTVisitor& _visitor)
 {
 	if (_visitor.visit(*this))